This invention relates to a color display panel in which a liquid crystal light switching array and a mosaic color filter are combined to form a liquid crystal display panel.
This display panel comprises a light switching array having a liquid crystal layer interposed between a pair of substrates, and a mosaic color filter provided on the light switching array.
The present invention especially relates to a method for manufacturing multicolored plates having fine and close pattern. The present invention also relates to a method for manufacturing a multicolor display device using a color filter.
One conventional method for manufacturing multicolored plates includes a coloring method utilizing surface diffusion of metal iron known as the so-called staining method, another coloring method comprises the printing and burning of low melting temperature glass frit and another coloring method utilizes printing ink containing organic polymer binder.
However, these conventional methods have various drawbacks. For instance the coloring method by printing has the drawback that the color layer is quite uneven and lacks clarity and therefore is not a good color layer. The staining method also has the drawback that the fabrication process is complicated by using strong heat and that the possible color tone is restricted though the surface of the substrate keeps its initial smoothness. In addition, these methods have the common drawback in making a fine multicolor pattern that they lack accuracy and that colors of different tones are mixed with each other at the boundary where the two different colors are divided in two portions.
Also known is a method for manufacturing multicolored plates by coloring anodically oxidized aluminum film which has the good points of smoothness of the colored layer, wide variety of possible color tone and easy fabrication.
This method comprises the steps of forming a thin film of aluminum on a base plate, changing this thin film of aluminum into a thin film of anodically oxidized material, coloring this thin film of anodically oxidized aluminum by use of organic or inorganic coloring materials and thereafter sealing the porosity on the surface of the anodically oxidized aluminum thin film so as to stablize the colored layer. Another method employs the photo-resist method or the sublimate transferring method utilizing thermal sublimation of a sublimate dye so as to divide the anodically oxidized aluminum thin film into different colors. The former method has the drawback that the fabrication process is complicated. The latter method has also the drawback that the possible color tone is limited due to a limited variety of the sublimated dyes and that a quite fine pattern is hard to obtain according to this method.
In manufacturing a multicolor display device with a color filter, it is difficult to coincide the pattern of the transparent electrode with the pattern of the color filter. The more fine and multicolored the patterns, the more difficult it becomes to coincide the patterns. The color filter can be formed by means of screen printing, photoresists or the like. In the case of screen printing, however, a pattern cannot be so finely made. Namely, the more the pattern is colored with several colors, the worse the precision of the printing portion is, and color shear occurs. In the case of a photoresist, a pattern can be made fine, but the processes are complicated.
The present invention uses a simplified method whereby display panels are produced with color proofing films applied in register with display electrodes.